Guest‐Induced Instant and Reversible Crystal‐to‐Crystal Transformation of 1,4‐Bis(ferrocenylethynyl)anthraquinone

1,4-Bis[2-(4-ferrocenylphenyl)ethynyl]anthraquinone from synchrotron X-ray powder diffraction

“…The angle between the CgÁ Á ÁCg vectors of the two terminal groups is 125.2 at 90 K, 125.6 at 300 K and 104.1 at 500 K. The dihedral angles between the two Ph groups and their respective adjacent Fe groups (Cg2 and Cg9, and Cg4 and Cg8) are listed in Table 2. The angle between Cg9 and Cg2 is much smaller at T = 500 K than at 90 and 300 K. Within the ferrocenyl groups, at T = 90 and 300 K, the two Cp rings are not eclipsed, in contrast with what was found for 1,4-Fc 2 Aq (Kondo et al, 2006). The Cg3Á Á ÁCg4 Fc group is nearly staggered at these temperatures.…”

“…The donor in the C52-H69Á Á ÁCg9 v interaction belongs to Cg4, a Cp group of the ferrocenyl which has a staggered conformation at 90 and 300 K, as opposed to the eclipsed conformation found for the Cp rings in other FcAq materials (Kondo et al, 2006;Murata et al, 2001). At temperatures below the phase transition, it would appear that the electrons of Cg9 v attract atom H69 to the point of rotating the donor Cg4 into a staggered conformation.…”

“…Many organic solvents, such as CH 2 Cl 2 , o-dichlorobenzene, tetrahydrofuran, trichloroethylene and hexane, can be entrapped in the porous phase (Kondo et al, 2006). In an attempt to expand the pore size, we synthesized the title compound, 1,4-(FcPh) 2 Aq, (I), by inserting phenylene rings between the ethynyl and ferrocenyl fragments.…”

“…The structure model for the GA was constructed using similar structures, viz. 1,4-Fc 2 Aq, 1,5-Fc 2 Aq and 1,8-Fc 2 Aq (Kondo et al, 2006;Murata et al, 2001). Chemically equivalent distances were set equal in the model.…”

Protonation‐Induced Cyclocondensation of 1‐Aryl Ethynylanthraquinones: Expanding the π Conjugation

“…Figure 1 b shows the packing structure of 5 . The average plane‐to‐plane distance between C6‐C7‐C8‐C9‐C10 and C11‐C12‐C13‐C26‐C25‐O1 is 3.287(4) Å, which indicates the existence of intermolecular donor–acceptor interactions 9…”